焙烧复原法制备山梨酸和苯甲酸插层水滑石及其缓释性能研究

Sorbic Acid and Benzoic Acid Intercalated Hydrotalcite via Calcine-Recovering Method: Preparation and Release Performances

焙烧复原法无需有机溶剂,制备流程比较简单,条件容易控制。以水滑石(LDH)为载体,通过焙烧复原法分别将山梨酸(SA)和苯甲酸(BA)插入其层间,制备了SA-LDH和BA-LDH插层材料。采用傅里叶变换红外光谱(FT-IR)、X-射线衍射(XRD)、热重-差热分析(TG-DSC)和扫描电镜(SEM)对其结构和热稳定性进行表征,并研究在不同pH缓冲体系中的缓释性能和机理。结果表明,SA和BA阴离子成功的插入到LDH层间,分散效果得到了明显改善。SA-LDH表现出良好的缓释性能,在pH 4.4、3.4的缓冲溶液中120 min后达到释放平衡,释放量分别为431.34、389.38 mg/g。BA-LDH存在突释现象,缓释性能不佳,释放时间30 min时达到平衡,在pH 4.4、3.4的缓冲溶液中释放量为353.22、304.17 mg/g, SA和BA的释放过程符合准二级动力学方程。焙烧复原法制备的SA-LDH材料具有良好的缓释性能,在防腐保鲜类食品包装材料中的应用具有重要意义。

The calcine-recovering method does not require organic solvents, the preparation process is relatively simple and the conditions are easy to control.The intercalated materials of SA-LDH and BA-LDH were obtained by intercalation of SA and BA into the sheets of hydrotalcites(LDH) via calcine-recovering method.The structure and thermal stability of intercalated materials were confirmed by FT-IR,X-ray diffraction(XRD),TG-DSC and SEM.The release performances of SA-LDH and BA-LDH materials were investigated in different pH buffer systems.Both SA and BA anions were successfully intercalated in the interlayer and the dispersion was improved obviously.SA-LDH had a good drug controlled release performance, the release amounts of SA-LDH were 431.34,389.38 mg/g in buffer solutions at pH 4.4,3.4 after 120 min, respectively.BA-LDH had a sudden release phenomenon and poor release performance, the release amounts of BA-LDH were 353.22,304.17 mg/g in buffer solutions at pH 4.4,3.4 after 30 min, respectively.The SA and BA release kinetic process could be fitted well by pseudo-second-order.By using calcine-recovering method, SA-LDH materials with good release performances were successfully prepared, which is of great significance for the application of LDH in anti-corrosion and fresh-keeping food packaging materials.